CVE-2020-29321Public exploitNetwork attack vector

Privileged telnet access via embedded default credentials

Published Jun 4, 2021 · Updated Aug 4, 2024

Hard-coded credentials in the telnet service of D-Link DIR-868L 3.01 allow remote attackers to gain privileged firmware access. The firmware startup script etc/init0.d/S80telnetd.sh exposes the username and points to etc/config/image_sign, which stores the cleartext password. Exploitation requires access to the firmware image and a reachable telnet service; the recovered default pair enables privileged access and sensitive-data extraction.

CVSS severity7.5
High
EPSS probability1.35%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Hard-coded credentials in the telnet service of D-Link DIR-868L 3.01 allow remote attackers to gain privileged firmware access. The firmware startup script etc/init0.d/S80telnetd.sh exposes the username and points to etc/config/image_sign, which stores the cleartext password. Exploitation requires access to the firmware image and a reachable telnet service; the recovered default pair enables privileged access and sensitive-data extraction.

The record

CVE
CVE-2020-29321
Published
Jun 4, 2021
Updated
Aug 4, 2024
Vendor
D-Link
Product
DIR-868L
Classifications
CWE-522, CWE-798, T1552.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 4, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=3.01

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

D-Link · DIR-868Lversion=3.01

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:N
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-522Insufficiently Protected Credentials
CWE-798Use of Hard-coded Credentials
T1552.001Unsecured Credentials: Credentials In Files

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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